Driving and stopping mechanism



Jan; 5, 1937. J. GOULDBOURN ET AL 2,066,344

DRIVING AND STOPPING MECHANISM Original Filed Sept. 7, 1933 5 Sheds-Sheet 1 Jan.5 1937. J. GOULDBOURN ETAL; 2,066,344

DRIVING AND STOPPING MECHANISM Original Filed Sept. 7, 1933 3 Sheets-Sheet 3 I n 114 164 6 y 7-\ (q 166 i \\Q 152 Patented Jan. 5, 1937 UNITED STATES PATENT OFFICE DRIVING. AND STOPPING MECHANISM Original application September 7, 1933, Serial No. 688,480. Divided and this application February 18, 1935, Serial No. 7,016.

October 11, 1932 In Great Britain 20 Claims. (01. 192-144) This invention is concerned with improvements in or relating to starting and stopping mechanisms particularly applicable to sewing machines for operating on thick stubborn materials such as leather.

An illustrative machine of this kind is disclosed in United States Patent No. 1,169,909 granted to Fred Ashworth, February 1, 1916, and also in the present inventors co-pending application, Serial No. 688,480, filedSeptember '7, 1933 for Sewing machine from which application the present application has been divided.

Usual machines of this kind employ mechanism for actuating the sewing instrumentalities which, while satisfactory for enabling the machine to sew efficiently, up to a speed of say five hundred stitches per minute or thereabouts, is not suited for enabling the machine to run at a relatively high speed, for example, to sew a thousand stitches per minute.

The objects of the invention are to provide novel and improved starting and stopping means particularly well adapted for stopping without shock and invariably at the same point in its cycle such a high speed machine as is contem-' plated.

With these and other objects in view, the present invention contemplates the provision in a high speed machine having a main shaft, a main clutch, high and low speed clutches, of means for opening the main clutch While the low speed driving clutch is closed. In the machine de scribed, the means for opening the main clutch is actuated by the main shaft automatically when the speed of the shaft is reduced sufficiently to be driven by the low speed clutch and a brake is provided to stop the machine with the parts in a predetermined position after the main clutch is opened.

In order that the nature of the present invention may be more clearly understood, an illustrative embodiment will now be described and the above objects of the invention and its several features will become apparent to those skilled in the art from said description.

In the drawings:

Figure 1 is a view from the left hand side showing the general form of. the illustrative machine; Figure 2 is a sectional view illustrating the high and low speed clutches on a co-untershaft of the machine; Figure 3 is a sectional view showing the driving and stopping mechanism on the main shaft of the machine; Figure 4 is a detail view looking from the left of the machine showing cer-- tain elements associated with the stopping mechanism of the machine; Figure 5 is a plan view illustrating part of the stopping mechanism of the machine; Figure 6 is an end View from the left hand side of. the machineshowingcertain parts of the stopping mechanism seen in Figure 5; and Figure 7 is a plan view showing part of the clutch tripping mechanism shown in Figure 5.

The said illustrative embodiment of the inven-: tion is a machine designed for sewing the outsoles of welted shoes to their welts and comprises a column I and a head casting 5. A main shaft I5 is arranged parallel to the front of the machine (i. e. from left to right) and has mounted on it a main driving clutch arranged to be driven by belts from a countershaft secured to the column I. The arrangement of the clutch (the construction of which will be described in detail hereinafter) is such that the shaft I5 is caused to run normally at a high speed in a clockwise direction looked at from the left of the machine when the starting treadle is fully depressed but can be caused to run at a lowspeed in the same direction by causing or allowing the treadle to occupy a position higher than its fully depressed position. Shaft l5 has secured .to it cranks and various cam members which actuate needle and other awl mechanisms of the machine.

The countershaft for transmitting power to the main shaft I5 and high and low speed driving clutch embodying the present invention will now be described. The countershaft l8 (Fig. 1) is supported in bearings 20, 22 secured to the machine near the lower end of the column and has fast and loose pulleys 24, 26 over which a belt passes from suitable line shafting. The countershaft has freely mounted on it a relatively small grooved pulley 28 coupledby a roundibelt 30 to a relatively large pulley 32 (Fig. 2) mounted on the main shaft l5 and a relatively large grooved pulley 34 which is arranged on shaft l8 behind the smaller pulley 28 is coupled by a belt 36 to a relatively small pulley 38 on the main shaft. Secured to the countershaft so as to rotate therewith, but being movable axially along it between the large and small pulleys 34 and 28 is a driving member 40 in the form of a disc which has fixed to its rear face a leather ring 42 arranged to engage and grip the large pulley 34 when the driving member 40 is moved rearwardly. The driving member 40 also has fixed on its front face a leather ring 44 which engages the small pulley '28 when moved forwardly. The driving member '40 has fixed to it a pin 46 which passes through a slot extending along and passing through the axis of the countershaft [8. A spring pressed plunger 48 mounted in the countershaft engages the pin 46 and normally presses the driving member forwardly into engagement with the small pulley 28 so that the small pulley is normally coupled to the countershaft. A circular plate 50 is secured to the countershaft in front of the small pulley and has a leather ring 52 secured to its rear face. The relatively small pulley 28 is free to move to a slight extent along theshaft and when the driving member 40 is moved along the shaft into engagement with it, the relatively small pulley is urged against the plate 50 and clamped between it and the driving member when the machine is being started. The driving member 40 is arranged to be moved to cause the machine to run at high speed against the action of the spring pressed plunger 48 away from the small pulley towards and into engagement with the large pulley by a treadle 54, normally raised by a spring 56 connected by an upwardly extending link 58 having universal connections at its ends to an arm 60 extending laterally from the end of a screw 62 which is threaded mto and through a fixed sleeve 64 supported by a bracket 68 on the machine column. The rear end of this screw bears against the forward end of a stud 68 mounted in'a bore in the forward end of the countershaft and bears at its rear end against the pin 46in the driving member 40. The arrangement is such'that when the treadle is raised the driving member engages the small driving pulley and by depressing the treadle the screw 62 is moved rearwardly, moving the driving member rearwardly out of. engagement with the small pulley and into engagement with the large pulley. The arrangement of the pulleys of the high and low speed driving clutch on the main shaft I5 of the machine is as follows. A bell-shaped member 10 encloses the left end of shaft I5 and pulley 38 is formed on the outside portion of the bell-shaped member. As shown in Fig. 3, the pulley 38 has two grooves in either of whichthe belt may be run to give a choice of high speeds.

To the rim of. the bell shaped member I0 is secured a disc-like member I2 which has a relatively long sleeve I4 encircling shaft I5 and is rotatably mounted upon a bush I6. Thus the disc-like member I2 forms a carrying member for the bell-shaped member H1. The relatively large pulley 32 is formed as an annulus mounted on the periphery of'the disc-like member 12 and is prevented from moving axially by contact with, respectively, a face on the bell-shaped member I0 and a radial flange on member 12. A radial bolt I8 (Fig. 3) passes through the relatively large pulley 32 and clamps to the inner face thereof a small block 82 within a recess 84. cut in the member I2. The recess 84 is approximately twice the length of the block 82 and provides a lost motion device between the high speed and low speed pulleys 38 and 32. The block 82 has a pin 86 projecting from its left face and engages the forked end of a short swinging lever 88, the inner end of lever 88 having a wedge-shaped portion 89 engages a recess in a stem 90 parallel to the main shaft I5 and housed within the sleeve I4 of the disc-like member. The said short swinging lever is pivoted about midway of its length on a pin 92 extending from member 12. The left hand end of the stem 90 projects beyond the end of shaft I5 and is turned inwardly across the latter. Shaft I5 has a bore 94 containing a sliding rod 96 (normally urged towards the'right by a spring 88) and its left end is threaded. Nuts I00iare provided on the threaded end of rod 96 to couple the rod to the stem 90 through which it 6 passes. The right hand end of rod 96 has fixed in it a pin I02 which projects radially through a slot in the main shaft I5. The pin I02 has secured on it a cam piece I04 outside the main shaft.

The disc-like member .12 is formed with a coned recess I06 to be engaged by a leather covered part I08 on a clutch member IIO keyed to and slidingly mounted on the main shaft I5. The right face of part I08 is arranged to be moved towards the right, when the machine is to be stopped, into engagement with a leather braking ring I I2 secured on the left face of a clutch supporting bracket H4. The clutch member IIO has a hub member on its right surrounding the main shaft and having an inclined groove II4 around its periphery. Freely mounted in groove H4 is a swash ring II6 having extending from it a little below the axis thereof pins II8 which are rotatably mounted in a swinging lever I20 surrounding the hub of clutch member I I0. The lever I20 has formed on it a ball I22 confined in spherical recesses in the ends of two axially alined screws I24 adjustably mounted in clutch supporting bracket II4 parallel to the main shaft. The lower side of lever I20 has pivoted on a pin I26 fixed init a block I28 arranged to be engaged by a block I30 forming a hook on a clutch-controlling lever I32. When the hooked end of lever I32 engages the block I28 on lever I 20 the part- I 08 of the clutch member I I 0 is held out of engagement with the recess I06 in member I2 against the action of springs I34 mounted in recesses formed in the hub of the clutch member H0 and engaging a collar I35 on'themain shaft I5, which springs tend to thrust the coned part of the clutch member into engagement with the recess I06. Also when the hooked end of the clutch lever is in engagement with the block on the swinging lever, the right face of the coned part of the clutch member H0 is brought into engagement with the leather braking ring II2 on the left end of bracket I I4 to stop the machine. The clutch member IIO rides into engagement with the driving -member 12 when the clutch lever I32 is out of engagement with the block I28 and because the pins II8 are below the axis of the main shaft I5 the swinging lever is caused to swing idly about the ball I22. When, how'- ever, the clutch lever I32 is allowed to engage the block I28 the swinging lever is prevented from swinging towards the left and is held stationary so that the clutch member H0 is moved to the left so as to disengage it from the bracket II4 and move it into engagement with the disc-like member 12 to drive the machine.

. The clutch lever I32 is secured mid-way of its length on a horizontal. shaft I36 rotatably mounted in the bracket H4 and the right arm of the lever I32 has a horizontal pivot I38 carrying a spring latch I40. The rear end of shaft I36 to which the clutch lever I32 is secured has fixed on it an arm MI and has threaded through it a vertical adjustable screw I42 arranged to be engaged by the upper end of a cam member I44 secured on a shaft I46 rotatably mounted in a bearing on the bracket H4. The shaft I 46 has fixed to it an arm I48 which is connected by a rod I50 to the treadle 54. This arrangement is such that during depression of the treadle 54 the upper end of the cam member I44 engages the lower end of the screw I42 in the arm I40 and thereby rocks shaft I36 in a direction todisengage the hooked end of the clutch lever I32 from the block I28 to allow the clutch to be closed. Pivotally mounted on a stud I52 fixed in the bracket I I4 is a cam lever I54. The lower end of the cam lever has on it a roll I56 (Fig. 6) actuated by a cam face I58 on cam I44. The lower end of cam lever I54 also has fixed on it a plate I60 over which latch I40 snaps when the treadle is pressed fully down. The upper arm of cam lever I54 has formed on it a ball I62 which enters a recess in a lever I64 (Figs. and 7) forming part of the mechanism for providing certain auxiliary movements to the stitching devices. The forward end of lever I64 is arranged at different times to be engaged by the cam piece I04 and also by a cam I66 on the main shaft. The rear end of lever I64 is secured to a substantially vertical pin I68 rotatably mounted'in a block I10 secured to a rocking shaft I12 rotatably mounted in bearings at the rear of the machine so that lever I64 can swing to rotate the rocking shaft I12 and can swing laterally so that its forward end moves along the main shaft. The pin I68 to which lever I 64 is secured has fixed on its upper'end a finger piece I14 the end of which enters a recess in a spring pressed horizontal plunger I16 (Fig. 5) mounted in block I10. The plunger I16 is arranged to engage a pin I18 fixed on the machine frame when lever I64 is raised to hold the lever in this position.

When the machine is to be stopped, the small pulley 28 on the countershaft I8 is coupled to the driving member 40, the relatively large pulley 32 on the main shaft I5 being thereby driven. The small pulley 38 on the main shaft I5 will rotate idly the relatively large pulley 24 on the counter shaft I8, which pulley at this time is freely rotatable on the countershaft. The lever I64 will in previous stopping of the machine have been raised by its cam I66 on the main shaft and will be held in raised position by the spring plunger I16 and will, through the rocking shaft I12,'be holding certain of the stitching devices in proper positions to facilitate starting the machine. When the treadle 54 is first depressed the cam member I44 is swung upwardly and through the vertical lever I54 which it actuates, swinging lever I64 away from its cam I66 and releasing the spring plunger I16 so that lever I64 can swing downwardly towards the main shaft and shaft I12 can rotate to allow the stitching devices to return to their operating positions. Upon further depression of. the treadle, the upper end of cam member I44 engages the lower end of screw I42 on the clutch lever and rocks shaft I36 in a direc tionto disengage the hooked end of the clutch lever from block I28 and allows the clutch to close, the machine being driven at the slow speed. When the treadle is still further depressed the right arm of lever I32 is raised still further by the cam I44 until latch I40 engages plate I60 on the lower end of cam lever I54 and during this further downward movement of the treadle the driving member 40 on the countershaft I8 is moved along the shaft out of engagement with small pulley 28 on the countershaft and into engagement with large pulley 34, the machine being then driven at the high speed. When the machine is being driven at high speed large pulley 32 on the main shaft is being driven by the engagement of the recess 84 in the periphery of the disc-like member 12 with the block 82 on the inner face of large pulley 32 and small pulley 28 on the countershaft then disengaged from the driving member 40 on the countershaft, is driven idly. Owing to the fact that recess 84 in the disc-like member 12 is wider than the block 82 relative movement about the axis of the main shaft between member 12 and large pulley 32 takes place when the speed ofthe main shaft is changed from the low speed to the high speed and vice versa. This relative movement causes lever 88 to swing about its pivot 92 and through its wedge-shaped inner end 89 to move stem 98 and rod 96. The springs 98 urge the rod towards the right and hold one face of the recess in the stem 90 against the swinging lever 88. The arrangement is such that when the machine is being driven at the high speed the cam I04 secured to the rod 96 is at the right end of its movement along the main shaft and. when the machine is being driven at the low speed the cam I04 is at the left end of its movement. When the cam is at the right end of its movement, it is removed from beneath lever I64 and when it is at the left end of its movement it is beneathsaid lever and raises the forward end of this lever.

If, when the machine is being driven at the high speed, it is desired that it shall be drivenat the slow speed, the treadle 54 may be allowed to rise so far only that the driving member 40 on countershaft I8 moves out of engagement with large pulley 34 and into engagement with small pulley 28. When the change of speed takes place, the relative movement between member 12 and large pulley 32 on the main shaft takes place due to the application of driving force through the large pulley and cam I04 is moved to the left along the main shaft and comes beneath the end of lever I64. As the'main shaft rotates, the lever I64 is raised somewhat by the cam I04 but the lever is prevented from swinging laterally by reason of its being held in its left-hand position by cam I44 and lever I54 which the cam operates. While the main shaft I5 is being driven at the slow speed, the clutch lever I32 is held in its inoperative position by the engagement of latch I40 on the right arm of lever I32 with plate I6 Il,.on lever I54. The lever I54 is held in place at this time by the cam I44 so that when the treadle 58 is allowed to rise, the cam being lowered, theclutch lever I32 is rendered operative without further delay.

When the treadle is allowed to rise fully, cam I44 which it operates releases the lever I54 and, when cam I04 raises the lever I64, this lever can swing to the right over cam I66 on the main shaft, when a low part of the latter cam comes into a position to allow it to do so. When a high part of cam I 66 engages lever I 64 as the cam rotates, this lever is rocked upwardly, thereby rotating shaft I12 in a direction to move certain of the stitching devices to predetermined positions. Lever I64 is held in its raised positionby plunger I18 during any further rotation of the main shaft. When lever I64 swings to the right after being raised by cam I04 it swings the lower end of lever I54 to the left and releases latch I40 on the right arm of lever I32 from plate I69 on the lower end of lever I54, so that the left end. of the clutch lever I32 can be raised, by a spring,'not shown, to position the hooked end of the lever in the path of the block I28 on lever I20. There after the lower end of lever I20 moves to thefleft and its swinging movement is stopped. As the main shaft continues to rotate, the clutch member H is moved out of engagement with the disclike member 12 and into engagement with the braking ring H2 on the clutch bracket I M to stop the main shaft.

It will be seen that this stopping arrangement is such as to bring the machine to rest always at the same point in the machine cycle Without undue shock, even though the machine berunning at high speed and the treadle be completely released suddenly. The definiteness of the stopping position is' assured by the fact that the application of the brake is directly controlled by the swash ring H6 on the main shaft l while the absence of shock is due to the impossibility of the swash ring becoming operative until the speed of the main shaft has fallen to the low driving speed, for it is only when the low speed driving pulley on the main shaft catches up the high speed pulley that the lost motion device consisting of the block 82 on the low speed pulley 32 and therecess 84 in the disc-like member 12 becomes active to stop the machine.

The nature and scope of the invention having been indicated, and a construction embodying the several features of the invention having been specifically described, what is claimed is:-

1. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch, high and low speed driving mechanism for driving the main clutch comprising high and low speed friction clutches, a treadle, treadle controlled connections acting to close the high,speed clutch as the low speed clutch is opened and to close the low speed clutch as the high speed clutchis opened, and means controlled both by said treadle and by the application of a driving force through the low speed driving mechanism for opening the main clutch.

2. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch, high and low speed driving mechanism for driving the main clutch, means for shifting from the high to the low speed driving mechanism, and means actuated by a change in speed of said shaft while the low speed driving mechanism is operative for opening the main driving clutch.

3. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch, high and low speed driving mechanism for driving the main clutch comprising high and low speed friction clutches, a treadle and suitable connections for controlling the friction clutches to shift from high to low speed, normally inoperative means actuated by said shaft for opening the main clutch, and an element controlled by a change in speed of the driven shaft for rendering the main clutch opening means operative. I

4. A driving and stopping mechanism having, in combinationQa driven shaft, a main driving clutch, a vibrating member actuated by the shaft and cooperating therewith when held from vibration to open the clutch, a latch to hold the member from vibration, high and low speed driving mechanisms for driving the clutch, and means controlled by the low speed driving mechanism andactuated by the shaft for causing the latch to engage the vibrating member.

5. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch comprising driving and driven members, a high speed pulley directly connected to the clutch.

driving clutch member, a low speed pulley concentric with the high speed pulley and having a limited angular movement with relation thereto, and means actuated by the shaft and controlled by said angular movement of the slowspeed pulley for opening the clutch while the shaft is being driven by the slow speed pulley.

6. A driving and stopping mechanism having, in combination, a driven shaft, a main driving clutch, high and low speed driving mechanisms for driving the clutch comprising high and low speed friction clutches, a treadle and suitable connections for controlling the friction clutches to drive the main clutch at either a high or a low speed,- means actuated by the shaft to open the main clutch, said means comprising a trip member arranged to be actuated by the treadle, an element for preventing actuation ,of said trip member, and means controlled by the application of a driving force through the low speed clutch for rendering the trip member operative to open the main clutch.

'7. A driving and stopping mechanism having, in combination, a main shaft, a main clutch therefor, high speed and low speed clutches for driving said. main clutch at high or low speed at the will of the operator, and means rendered operative by a change in speed of rotation of the main shaft for opening the main driving "combination, a main shaft, high and low speed clutches for driving said shaft at high speed or low speed at will, means for ensuring that, on the starting of the machine into operation, the low speed clutch will come into driving operation before the highspeed clutch and will remain in driving operation after the high speed clutch has been disengaged, and means controlled by the application of a driving force through the low speed clutch for stopping the machine.

10. A driving and stopping mechanism having, in combination, a main shaft, a main clutch onsaid shaft comprising a driving and a driven member, a high speed pulley directly connected to the driving member, a low speed pulley having a limited angular movement relatively to the high speed pulley, a cam on the shaft, means actuated by the main clutch shaft comprising a trip lever arranged to be actuated by the cam when it is being driven at low speed, and a controlling device for said trip lever arranged to prevent actuation of it by said cam when the shaft is rotating at high speed, but to release it for actuation by the cam when the machine has fallen to low speed.

11. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms driving mechanism when the shaft is driven at high speed for Opening the main clutch.

12. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms for rotating the driving clutch member, a treadle for closing the main clutch and for rendering either of said mechanisms effective at will, and means actuated by the driving force of said drivingmechanisms when the speed of the shaft is above the speed of the low speed driving mechanism for preventing the main clutch from being opened.

13. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms for rotating the driving clutch member, a treadle for closing the main clutch and for rendering either of said mechanisms effective at will, a trip member arranged to hold the main clutch closed after the high speed driving mechanism is rendered effective by the treadle, and connections actuated by the application of a driving force through the low speed driving mechanism to release the trip member and cause the main clutch to be opened.

14. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, a counter-shaft, high and low speed clutches on the counter-shaft, driving connections for rotating the main driving clutch member from said high and low speed clutches, a treadle for causing the low speed clutch to be closed when the high speed clutch is opened, the low speed clutch to be opened when high speed clutch is closed, and the main clutch to be opened only when the low speed clutch is closed, and an element shiftable by a change in speed of the main shaft to prevent opening of the main clutch while the main shaft is rotated at high speed.

15. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, a counter-shaft, high and low speed clutches on the counter-shaft, driving connections for rotating the main driving clutch member from said high and low speed clutches, a treadle for causing the low speed clutch to be closed when the high speed clutch is opened, the low speed clutch to be opened when the high speed clutch is closed, and the main clutch to be opened only when the low speed clutch is closed, and means actuated by a change in speed of the main shaft for delaying the opening of the main clutch after the high speed clutch is opened.

16. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms for rotating the driving clutch member, a treadle for closing the main clutch and for rendering either of said mechanisms effective at will, a trip member arranged to hold the main clutch closed after the high speed driving mechanism is rendered effective by the treadle, a cam on the main shaft for releasing the trip member, and connections controlled by the low speed driving mechanism when the speed of the shaft is above the speed of the low speed driving mechanism for preventing the cam from releasing the trip member.

17. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms for rotating the driving clutch member, a treadle for closing the main clutch and for rendering either of said mechanisms effective at will, a trip member arranged to hold the main clutch closed after the high speed driving mechanism is rendered effective by the treadle, a cam on the main shaft, a follower normally out of the range of the cam for releasing the trip member when actuated by the cam, and connections controlled by the low speed driving mechanism when the speed of the shaft is the same as the speed of the low speed driving mechanism to bring the follower into the range of the cam.

18. A driving and stopping mechanism having, in combination, a main driven shaft, a main driving clutch comprising driving and driven members, high and low speed driving mechanisms for rotating the driving clutch member, a treadle for closing the main clutch and for rendering either of said mechanisms effective at will, a trip member arranged to hold the main clutch closed after the high speed driving mechanism is rendered effective by the treadle, a lever for releasing the trip member, a cam on the main shaft normally out of position to engage the lever, and connections controlled by the low speed driving mechanism when the speed of the shaft is the same as the speed of the low speed driving mechanism to bring the cam into a position where it will engage the lever.

19. A driving and stopping mechanism having, in combination, a main shaft, a main clutch on the shaft, a brake for bringing the shaft to rest, means inciuding a cam on the shaft for causing the clutch to be opened and the brake to be applied at predetermined angular positions of the shaft, a rod arranged in parallel relation to and rotating with the shaft for changing the position of the cam to render it effective or ineffective in stopping the shaft, and means for actuating the rod.

20. A driving and stopping mechanism having, in combination, a main shaft, a main clutch on the shaft, a brake for bringing the shaft to rest, means including a cam on the shaft for causing the clutch to be opened and the brake to be applied at predetermined angular positions of the shaft, a rod arranged in parallel relation to and rotating with the shaft for changing the position of the cam to render it effective or ineffective in stopping the shaft, and means for shifting the rod to cause the cam to be ineffective when the shaft is rotating above a predetermined speed.

JOSEPH GOULDBOURN. THOMAS AUBREY KESTELL. FRANK BYCROFT KEALL. 

